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Full-Text Articles in Earth Sciences

Giants Among Micromorphs: Were Cincinnatian (Ordovician, Katian) Small Shelly Phosphatic Faunas Dwarfed?, Benjamin F. Dattilo, Rebecca L. Freeman, Winfried S. Peters, William P. Heimbrock, Bradley Deline, Anthony J. Martin, Jack W. Kallmeyer, Jesse Reeder, Anne Argast Feb 2016

Giants Among Micromorphs: Were Cincinnatian (Ordovician, Katian) Small Shelly Phosphatic Faunas Dwarfed?, Benjamin F. Dattilo, Rebecca L. Freeman, Winfried S. Peters, William P. Heimbrock, Bradley Deline, Anthony J. Martin, Jack W. Kallmeyer, Jesse Reeder, Anne Argast

Winfried S. Peters

Small fossils are preserved as phosphatic (carbonate fluorapatite) micro-steinkerns (∼ 0.5 mm diameter) in Upper Ordovician beds of the Cincinnati area. Mollusks are common, along with bryozoan zooecia, echinoderm ossicles, and other taxa. Similar occurrences of Ordovician micromorphic mollusks have been interpreted as ecologically dwarfed and adapted to oxygen-starved conditions, an interpretation with implications for ocean anoxia. An alternative explanation for small phosphatic steinkerns is taphonomic. Stable carbonate fluorapatite selectively filled small voids, thus preserving small fossils, including larval/young mollusks. Reworking concentrated small phosphatic steinkerns from multiple generations while larger, unfilled calcareous shells were destroyed, resulting in small fossils progressively …


The Orientation Of Strophomenid Brachiopods On Soft Substrates, Roy Plotnick, Benjamin Dattilo, Daniel Piquard, Jennifer Bauer, Joshua Corrie Jul 2014

The Orientation Of Strophomenid Brachiopods On Soft Substrates, Roy Plotnick, Benjamin Dattilo, Daniel Piquard, Jennifer Bauer, Joshua Corrie

Benjamin F. Dattilo

Strophomenid brachiopods have long been interpreted as ‘‘snowshoe’’ strategists, with their flattened concavoconvex valves providing resistance to foundering in very soft sediments. There has been a sharp difference of opinion in whether the shells were oriented with their convex or their concave surface in contact with the sediment. This study, along with independent evidence from sedimentology, ichnology, and morphology, indicates that the strophomenids lived with their shells concave down (convex up). Experiments indicate the force required to push shells into soft cohesive muds is much greater for the convex up than for the convex down orientation. Forces also increase with …


The Evolution Of Billfish, Andrew Blitman Dec 2013

The Evolution Of Billfish, Andrew Blitman

Andrew Blitman

No abstract provided.


The “Curse Of Rafinesquina:” Negative Taphonomic Feedback Exerted By Strophomenid Shells On Storm-Buried Lingulids In The Cincinnatian Series (Katian, Ordovician) Of Ohio, Rebecca Freeman, Benjamin Dattilo, Aaron Morse, Michael Blair, Steve Felton, John Pojeta Dec 2012

The “Curse Of Rafinesquina:” Negative Taphonomic Feedback Exerted By Strophomenid Shells On Storm-Buried Lingulids In The Cincinnatian Series (Katian, Ordovician) Of Ohio, Rebecca Freeman, Benjamin Dattilo, Aaron Morse, Michael Blair, Steve Felton, John Pojeta

Benjamin F. Dattilo

Taphonomic feedback is the idea that accumulation of organic remains either enhances the habitat for some organisms (positive taphonomic feedback), and/or degrades the habitat for others (negative taphonomic feedback). Examples of epibionts living on skeletal remains are direct evidence of positive taphonomic feedback. Disruption of infaunal burrowing activities by skeletal fragments is an example of negative taphonomic feedback; direct fossil evidence of this phenomenon has not been documented previously. Infaunal organisms are vulnerable to exhumation or entombment during storms, but organisms that burrow can also re-establish viable life positions subsequently. For example, when modern lingulids re-burrow after exhumation, they first …


Sharks Of The Devonian, Andrew Blitman Dec 2011

Sharks Of The Devonian, Andrew Blitman

Andrew Blitman

No abstract provided.